In recent years, as smart meters have become widespread, technologies for supplying users with total power consumption (instantaneous values) in predetermined units (a household, a company, a floor of one building, or the like) have been standardized. By providing not only total power consumption in the predetermined units but also power consumption (instantaneous values) of an electrical device as a single body used in the predetermined units, measures for more precise power saving are expected to be prompted.
Power consumption of an individual electrical device can be ascertained, for example, by mounting a measuring instrument on each electrical device. However, in the case of this method, a workload of mounting a measuring instrument on each electrical device is considerable. Further, a cost burden increases since the number of measurement instruments increases with an increase in the number of electrical devices.
The related technologies are disclosed in Patent Documents 1 to 6.
Patent Documents 1 and 2 disclose technologies for installing a measuring instrument in a power trunk line portion such as a power-feeding service entrance or a distribution board and inferring an operation state of each electrical device using measurement data (a total current consumption waveform or the like) measured with the measuring instrument. In the technologies, a feature amount (a training feature amount) at the time of operation of each electrical device is prepared in advance and a sum training feature amount in which the training feature amounts are summed in any combination is further prepared in advance. Then, based on feature amounts extracted from the measurement data measured in the power trunk line portion and the training feature amounts (including the sum training feature amounts) prepared in advance, an operation state of each electrical device is inferred.
Patent Document 3 discloses a technology for generating a training feature amount indicating a feature amount at the time of an operation of each electrical device. Specifically, pieces of predetermined data (current consumption or the like) are individually measured by operating electrical devices in a house to be measured one by one. A feature amount is extracted from the measured data of each of the electrical devices and the extracted feature amount is stored as a training feature amount.
Patent Document 4 discloses a power consumption measurement system that includes a data extraction unit and an inference unit. The data extraction unit extracts averaged current waveform data averaged per one period of a commercial frequency of a total load current based on a total load current and a voltage measured at a predetermined position of a leading wire in an area of demand and extracts convex point information regarding a convex point indicating a point at which change in a current value is changed from an increase to a decrease or a point at which the change in the current value is changed from the decrease to the increase from the averaged current waveform data. The inference unit retains an inference model in which a classification of an electrical device, the convex point information, and power consumption are associated with each other in advance and individually infers the power consumption of the electrical device being in operation based on the convex point information extracted by the data extraction unit and the inference model.
Patent Document 5 discloses a remote electrical device monitoring method of inferring operation statuses of a plurality of electrical devices used by a customer. In the method, a total load current is measured at a power feeding line of a customer, the total load current is converted into a current for the basic wave and each harmonic, and a temporal difference in the current for the basic wave and each harmonic is obtained to generate current change data. The current change for the basic wave and each harmonic is separated into each component inferred as a device group having an identical harmonic intensity ratio through independent component analysis. Then, an operation status (current change) of each monitoring target device is inferred from the waveform of the current change for each component having an identical harmonic intensity ratio.
Patent Document 6 discloses a power consumption amount inference device that infers a power consumption amount of a load device to which power is supplied from a power system. The device receives an operation state signal indicating a value according to an operation state of a load device and determines whether the load device is an operated load device in an operation state based on the value indicated by the received operation state signal. As an inferred power consumption amount of a newly operated load device, a change amount in the total power consumption amount before and after the change is allocated. A previously allocated inferred power consumption amount is allocated as an inferred power consumption amount of an operated load device other than the newly operated load device to the operated load device.